U.S. patent application number 15/742690 was filed with the patent office on 2018-07-12 for airflow control device.
The applicant listed for this patent is Elipcon AB. Invention is credited to Fredrik Ekstrand, Tobias Sagstrom.
Application Number | 20180195756 15/742690 |
Document ID | / |
Family ID | 53673749 |
Filed Date | 2018-07-12 |
United States Patent
Application |
20180195756 |
Kind Code |
A1 |
Sagstrom; Tobias ; et
al. |
July 12, 2018 |
AIRFLOW CONTROL DEVICE
Abstract
Airflow control device (1) for use in an air handling system,
which comprises an outer tube (2) and at least one inner tube (3)
arranged inside the outer tube (2). The inner tube (3) is at least
partly made of flexible material and has an axial opening (4)
through which air is adapted to flow. The inner tube (3) further
exhibits an inlet part (8) and an outlet part (10), and a throttle
part (9) between the inlet part and the outlet part. The device (1)
is characterized by a pivotable throttling device (7) which is
arranged to impact the inner tube (3), and thereby control the
airflow through the inner tube (3), by rotation around a second
pivot axis (b).
Inventors: |
Sagstrom; Tobias;
(Jonkoping, SE) ; Ekstrand; Fredrik; (Jonkoping,
SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Elipcon AB |
Jonkoping |
|
SE |
|
|
Family ID: |
53673749 |
Appl. No.: |
15/742690 |
Filed: |
July 1, 2016 |
PCT Filed: |
July 1, 2016 |
PCT NO: |
PCT/EP2016/065517 |
371 Date: |
January 8, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F24F 13/10 20130101;
F24F 13/14 20130101; F24F 13/02 20130101; F24F 13/0218
20130101 |
International
Class: |
F24F 13/10 20060101
F24F013/10; F24F 13/02 20060101 F24F013/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 10, 2015 |
EP |
15176203.6 |
Claims
1. Airflow control device (1) for use in an air handling system,
which airflow control device (1) comprises an outer tube (2), and
further at least one inner tube (3) arranged inside the outer tube
(2), which inner tube (3) at least partly is made of flexible
material, the inner tube (3) has an axial opening (4) through which
air is adapted to flow, and the inner tube (3) further exhibits an
inlet part (8) and an outlet part (10), and a throttle part (9)
between the inlet part (8) and the outlet part (10), the airflow
control device (1) further comprising a pivotable throttling device
(7) which is arranged to impact the inner tube (3), and thereby
control the airflow through the inner tube (3), by rotation around
a second pivot axis (b), which second pivot axis (b) is at least
near perpendicular to a central axis (a) of the inner tube (3).
2. The airflow control device (1) according to claim 1, wherein the
pivotable throttling device (7) is arranged between the outer tube
(2) and the inner tube (3).
3. The airflow control device (1) according to claim 1, wherein the
pivotable throttling device (7) is arranged inside the inner tube
(3).
4. The airflow control device (1) according to claim 1, wherein the
pivotable throttling device (7) is arranged inside a pocket
arranged at the inner tube (3).
5. The airflow control device (1) according to claim 1, wherein the
inlet part (8) and the outlet part (10) respectively exhibits an
asymmetrical cone shape during throttling by the throttling device
(7).
6. The airflow control device (1) according to claim 1, wherein the
throttling device (7) is made of wire-like material.
7. The airflow control device (1) according to claim 1, wherein the
throttling device (7) is made of steel sheet material.
8. The airflow control device (1) according to claim 1, wherein the
inner tube (3) comprises a first end (5) and a second end (6) which
are respectively attached at corresponding ends of the outer tube
(2).
9. The airflow control device (1) according to claim 1, wherein the
throttling device (7) is a pivotable ring (11) which is pivotally
mounted in the outer tube (2).
10. The airflow control device (1) according to claim 1, wherein
the length (1) of the throttle part (9) increases while the radial
size of the axial opening (4) decreases during throttling.
11. The airflow control device (1) according to claim 1, wherein
the throttling device (7) is a pivotable arc (12) which is
pivotally mounted in the outer tube (2).
12. The airflow control device (1) according to claim 1, wherein
the throttling device (7) is connected to a rotatable shaft (13),
accessible from outside the outer tube (2).
13. The airflow control device (1) according to claim 12, wherein
the rotatable shaft (13) is connected to an actuator (14), for
controlling the airflow through the airflow control device (1).
14. The airflow control device (1) according to claim 1,
characterized by that wherein the flexible material of the inner
tube (3) comprises fabric, textile, cloth, plastics or rubber.
Description
FIELD OF INVENTION
[0001] Present invention relates to an airflow control device for
use in the field of ventilation, and provides a simple, cost
efficient and very silent airflow control device compared to
existing control devices like the IRIS-damper or conventional blade
dampers .
BACKGROUND OF THE INVENTION
[0002] In the field of ventilation airflow control is essential and
many airflow control devices/dampers are known. A very simple and
cost efficient type is the so-called blade damper.
[0003] This damper consists of a rotatable blade arranged inside an
outer tube, and which blade can be rotated around a rod fitted in
the outer tube. Preferably the blade comprises a sealing around its
periphery to prevent leakage in the closed position. By rotating
the blade, more or less of the airflow passage is covered by the
blade and thereby it is possible to control or stop the airflow
passing through the tube. Unfortunately this damper type causes a
lot of turbulence of the airflow and thereby a lot of noise which
are unwanted characteristics and a problem within ventilation.
[0004] Another well-known damper is the so-called IRIS-damper,
which changes the size of the airflow passage via an iris-like
radial movement of a number of thin steel sheet blades.
[0005] This is a good solution for controlling the airflow, but
unfortunately also a very noisy solution with a complex and cost
driving design.
[0006] A recent solution is presented in EP 2 492 606 A1, which is
an airflow adjustment device for arrangement in an air ventilation
arrangement, and which comprises an outer tube, an inner tube
arranged inside the outer tube and rotationally and axially
moveable relative to the outer tube. Further the device comprises a
twist tube with an axial opening through which air is adapted to
flow. The twist tube is fixed relative to the outer tube with one
end and attached to the inner tune at the second end. The inner
tube is adapted to be rotated and displaced relative to the outer
tube and when the inner tube is rotated the twist tube is twisted
and the size of the axial opening is changed. This device is far
better regarding noise compared to the previous presented devices,
but it has a complicated design and is therefore expensive to
manufacture. For all the above described prior art solutions a
consequence of increased throttling, i.e. the closing of the
damper, is increased turbulence and thereby increased noise.
[0007] Because of the above described shortcomings of existing
dampers there is a need for a simple and cost-efficient air control
device with better characteristics regarding noise and airflow
control, preferably over a wide range of airflows for the specific
size of the airflow control device.
DISCLOSURE OF THE INVENTION
[0008] It is an object of the present invention to provide a
solution which overcomes the problems stated above and this is
achieved by an airflow control device as described below. The
airflow device comprises an outer tube and at least one inner tube,
arranged inside the outer tube, and which inner tube at least
partly comprises flexible material. The air is adapted to flow
through an axial opening of the inner tube. The inner tube further
comprises an inlet part and an outlet part, and a throttle part
between the inlet part and the outlet part. The inlet part,
throttle part and outlet part may together form the shape of the
inner tube. The inner tube comprises a central axis. By the
throttle part being located between the inlet part and the outlet
part it may be meant that the throttle part is arranged between the
inlet part and the outlet part along the central axis of the inner
tube. The inner tube may be aligned with the outer tube to have a
common central axis of the device which also is common with the
airflow direction through the device. To regulate the airflow
through the device, a pivotable throttling device is arranged to
impact the inner tube by a rotational movement around a pivot axis.
When the throttling device is rotated around its pivot axis the
form of the inner tube changes by the influence of the throttling
device and thereby airflow through axial opening of the inner tube
is controlled. This is possible because the inner tube or at least
a part of the inner tube is made of flexible material. The pivot
axis is perpendicular or at least near perpendicular in relation to
the central axis of the inner tube. By this configuration a
combination of advantages are achieved both according to
manufacture aspects and flow control aspects. As described above is
the known blade damper cost-efficient, and the benefits from that
design is used in the present invention through the pivotable
design of the throttling device. The pivot/rotation movement is
easy to apply and control. Further the advantages from the recent
solution presented in EP 2 492 606 A1 is at least partly used, by
that the inner tube is made of flexible material, or at least
partly made of flexible material. By allowing the throttling device
to impact the flexible inner tube, instead of directly impact the
air stream, a smooth and gentle throttling is achieved, with
positive characteristics according to turbulence and noise.
Depending of the specific design (different embodiments are
described below) of the throttling device it is possible to achieve
a controlled and tested design of the inlet part, the throttle part
and the outlet part of the inner tube, with preferred pressure loss
and sound characteristics. This solution provides a smooth airflow
passage through the device with no sharp edges like for example the
blade damper. Further, the deflecting of the air stream that occurs
in all throttle solutions and which causes the turbulence at the
throttle part, is controlled and not that abrupt as in prior art
solutions, because of the smooth passage through the inlet part,
the throttle part and the outlet part by the indirect and pivoting
arrangement. The present invention is causing less noise and has a
very simple construction and is thereby, more cost-efficient
compared to prior art solutions.
[0009] According to an embodiment of the invention the pivotable
throttling device is arranged between the outer tube and the
flexible inner tube. By rotating the throttling device around its
pivot axis the inner tube is effected from the outside and inwards
towards the centre. The impact from the outside together with the
flexible material in the inner tube provides smooth transitions to
the inlet part, the throttle part and the outlet part, which is
positive for pressure loss, turbulence and sound. This embodiment
is preferably performed with a thin throttling device which then
may be arranged between the outer and the inner tube without any
particular impact on the respective cross-sections of the tubes,
but it may also be a thicker throttling device with a certain
impact for example on the inner tube. This could be an alternative
if a design pressure loss is wanted in the specific case.
[0010] According to an alternative embodiment the pivotable
throttling device is arranged inside the inner tube. By this
arrangement the inner tube is for example has a smaller
cross-section in the unaffected state or is of collapsible
material, and the inner tube is in this case expanded to its open
position by the throttling device and collapses/throttles while
rotating the throttling device to a more throttled airflow.
Preferably the throttling device is thin or designed in way to not
causing noise or other unwanted characteristics.
[0011] According to another alternative embodiment the pivotable
throttling device is arranged inside a pocket or pocket-like
arrangement at the inner tube. To avoid that the material of inner
tube is torn, it may be wise to arrange the throttling device
inside a tight pocket arranged at the inner tube, which prevents
the throttling device from sliding over the surface of the inner
tube. If this is not a problem, i.e. the material can withstand
some wear, or if the pocket is made of durable material, the pocket
can be elongate and the throttling device can slide inside the
pocket. The same advantages regarding flow and sound
characteristics as the above described embodiments are at hand also
in this embodiment.
[0012] In another embodiment of the invention the inlet part and
the outlet part of the inner tube respectively exhibits an
asymmetrical cone shape during throttling by the throttling device.
This means that the as soon the throttling is initiated the
respective cone gets a grade of asymmetry, i.e. has a portion of
steeper walls which gradually turns into a flatter portion of the
inlet/outlet cone. By this the turbulence around the throttle part
is in most cases decreased, which is positive regarding pressure
and sound characteristics.
[0013] In a further embodiment of the invention the throttling
device is designed as a wire or a wire-like design, and thereby
thin. A thin throttling device makes as little impact on the
cross-section of both the outer tube and the inner tube. The outer
tube may in that case be an ordinary duct-type with no extra space
provided for the throttling device. Also the inner tube may have
almost the same cross-section as the outer tube, just slightly
smaller to fit inside the outer tube. This means that both the
outer and the inner tube may be designed as simple and
production-friendly tube which is cost-efficient, and any
turbulence that may occur is minimal, compared to prior art
solutions. The wire-like design may comprise any kind of material
such as plastic, steel-wire, rubber, etc.
[0014] In an alternative embodiment the throttle device is designed
from steel sheet material which makes it possible to produce a thin
throttling device similar to the wire-like design presented
above.
[0015] In one embodiment the inner tube comprises a first end and a
second end which are respectively attached in the outer tube, at a
distance from each other. This means that the inner tube is formed
by attachment to the outer tube. If the inner tube is made of
stretchable material the inner tube is preferably stretched out and
fixed near the ends of the outer tube to form the inner tube, and
the throttling device thereby can flex the inner tube during
throttling, while the ends of the inner tube are fixed. If the
inner tube is flexible, or partly flexible, but not stretchable,
the fastening of the ends to the outer tube still doesn't exclude
that the inner tube can be throttled by the throttling device in
the flexible part.
[0016] In an embodiment the throttling device is designed as a
pivotable ring, which is pivotally mounted in the outer tube and
pivotable around the pivot axis. The ring is easy to manufacture
and also easy to apply pivotally inside the outer tube. Further,
the ring-form provides in a throttled position an inlet part, a
throttle part, and an outlet part of the inner tube where the inlet
part and the outlet part are asymmetrical and cone shaped. Also,
the inlet and outlet parts are inverted, which in tests has proven
positive for turbulence and noise characteristics. The good test
results are also achieved by that the throttle part mainly exhibits
a form of a straight duct, because of that the ring is symmetrical,
i.e. two symmetrical arcs that affects the inlet part and the
outlet part. Tests have also showed that increased throttling
doesn't dramatically impair noise characteristics like in prior art
solutions.
[0017] In one embodiment, the axial length of the throttle part
increases the more the throttling of the airflow is performed. This
means that when the axial opening accessible for airflow through
the device decreases, the longer the throttle part gets. As
mentioned above, the throttle part mainly exhibits a form of a
straight duct, which gets a more even flow profile the longer
"duct" gets, which is proven positive during testing of the
product. This also means that the noise caused by throttling
doesn't increase as dramatic as in prior art solutions. I.e. the
airflow through the throttle part may be straight, even though it
follows a line having an angle towards the central axis of the
inner tube. The airflow is curved when entering the throttle part
from the inlet part, and when leaving the throttle part to the
outlet part. By throttling, the length and width of the throttle
part may be changed.
[0018] An alternative to the above presented ring is in a half
ring--a pivotable arc, which is pivotable around the pivot axis in
the same way as the ring. This is an even more cheap solution and
provides the possibility to choose whether to rotate the arc in
direction "towards" the airflow or "with" the airflow direction,
which may be of importance for sound characteristics. Further, the
pivotable arc may be formed as part of a ring being more or less
than a half ring.
[0019] To be able to rotate the throttling device arranged inside
the outer tube, the throttling device is connected to a rotatable
shaft according to one embodiment. The shaft is accessible from the
outside of the outer tube and a rotation of the shaft rotates the
throttling device and thereby changes the airflow through the
device. The shaft may extend from the throttling device radially
outward through the outer tube. In an embodiment wherein the
throttling device is arranged inside the inner tube, or in a pocket
in connection to the inner tube, the shaft may extend also through
the inner tube.
[0020] According to a further embodiment the shaft is connected to
an actuator for the possibility to automatically control the
airflow through the device. Through the simple design of the
complete airflow control device it is very easy to apply an
actuator of standard type and also the pivoting movement of the
throttling device makes it easy to control the airflow with a low
power actuator.
[0021] According to another embodiment, the flexible material of
the inner tube comprises fabric, textile, cloth, plastics, rubber
or the like. The flexible material may be configured to be bendable
or twistable by the throttling device to control the airflow. A
flexible material of plastics or rubber may comprise thin plastics
or rubber flexible such as fabric, textile or cloth.
[0022] By the invention a number of advantages compared to known
solutions are obtained: [0023] A simple and cost efficient design
with few parts and easy to manufacture. [0024] A very silent air
control device with better sound characteristics compared to most
prior art solutions. [0025] A designable form of the airflow
passage by different types of throttling devices. [0026] Easy to
clean due to that the throttle part is completely openable. [0027]
Easy to control by an actuator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1a-c shows a first embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in an open position.
[0029] FIG. 2a-c shows a first embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in a slightly throttled position.
[0030] FIG. 3a-c shows a first embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in a more throttled position than in FIG. 2a-c.
[0031] FIG. 4a-c shows a first embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in a nearly closed position.
[0032] FIG. 5a-c shows a second embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in an open position.
[0033] FIG. 6a-c shows a second embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in a slightly throttled position.
[0034] FIG. 7a-c shows a second embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in a more throttled position than in FIG. 6a-c.
[0035] FIG. 8a-c shows a second embodiment of the airflow control
device 1 in a cross section, a perspective view and a section, when
the device is in a nearly closed position.
[0036] The constructive design by the present invention is obvious
in the following description in detail of examples of embodiments
of the invention related to the accompanying figures showing a
first and second, but not limiting examples of embodiments of the
invention. In addition the invention forwards the prior art in the
field in different aspects. This is realized in the present
invention by that the device of the below described art principally
is constituted in a way that is obvious from the characterised part
of claim 1.
DETAILED DESCRIPTION OF THE DRAWING
[0037] FIG. 1a-c shows a preferred embodiment of the airflow
control device 1 with an outer tube 2 and an inner tube 3 of
flexible material arranged inside the outer tube 2. The tubes 2, 3
are aligned around a common first central axis a. In the preferred
embodiment the inner tube 3 has a cross section slightly smaller
than the outer tube 2, but smaller dimensions of the inner tube 3
is also possible. The airflow control device 1 is further arranged
with a throttling device 7, which is arranged between the outer
tube 2 and the flexible inner tube 3 and pivotable around a second
pivot axis b. The second pivot axis b is perpendicular, or close to
perpendicular in relation to the first device axis a. In other
words, the second pivot axis b is arranged substantially
perpendicular to an intended airflow direction through the device
1. By that the throttling device 7 is arranged between the outer
tube 2 and the inner tube 3 it may press the inner tube 3 from its
periphery and inwards when throttling, by a rotational motion
around the second pivot axis b. Further, the throttling device 7 is
thin not to impact the inner tube 3 more than necessary. In the
preferred embodiment the throttling device 7 is designed as a
pivotable ring 11, which is pivotally mounted in the outer tube
2.
[0038] In this embodiment the ring 11 is not attached at the inner
tube 3, but instead free to slide along the outer surface of the
inner tube 3 during throttling/opening. The throttling device 7 may
have any kind of wire-like design and consist of steel wire,
rubber, plastic or similar, or for example consist of a thin steel
sheet ring form. The throttling device 7, i.e. the ring 11 is in an
open position, wherein an axial opening 4 of the inner tube 3 is
fully open for airflow through the inner tube 3. The airflow
direction is shown by arrows in FIG. 1c. It is preferred that a
first end 5 and a second end 6 is respectively attached at the
corresponding ends, or near the ends of the outer tube 2, and
thereby at a distance from each other, preferably to form the shape
of the inner tube 3. For example, the inner tube 3 may comprise
stretchable material which is fixedly attached to one end of the
outer tube 2 and then stretched and fixed to the other end to form
the inner tube 3 in an appropriate way. Another option is that the
inner tube 3 isn't stretchable, but anyway flexible, and thereby
allowing the ring 11 to impact the material to throttle the inner
tube 3. The inner tube 3 may also be a "stand alone" inner tube 3
which is insertable in the outer tube 2 as a self-carrying flexible
tube inside the outer tube 2.
[0039] As explained above is the ring 11 arranged between the outer
tube 2 and the inner tube 3, but other alternatives are possible
within the scope of the invention. For example, the ring 11 may be
arranged inside a tight pocket or an elongated pocket, which is
fitted on the inner tube 3. Another alternative may be a ring 11
arranged inside the inner tube 3. The latter option could for
example be a stretched inner tube 3 of a small diameter, which then
is widened by the ring 11 in the open position and then by the
stretch and the smaller diameter will "collapse" during
throttling.
[0040] FIG. 2a-c shows the device 1 as described in FIG. 1a-c,
where the throttle device 7, i.e. the ring 11 is in a slightly
throttled position. In FIG. 2a the ring 11 is pivotally mounted in
the outer tube 2 and also connected to a rotatable rod 13, which in
turn is connected to an actuator 14. This is a simple solution for
automatic regulation of the airflow, with known devices for
motorization of the device 1. When throttling, the ring 11 directly
comes in contact with the inner tube 3 from the open position and
further slides along the inner tube 3, which is pushed from the
outside and inwards and in a throttled position the inner tube 3
exhibits an inlet part 8, a throttle part 9, and an outlet part 10,
as seen in FIG. 2b-c. It can also be seen that the inlet part 8 and
the outlet part 10 exhibits an asymmetrical cone shape, which in
tests proven positive for turbulence and noise characteristics. The
good test results are also achieved by that the throttle part 9
mainly exhibits a form of a straight duct, which is more visible in
FIG. 3c, below. Tests have also showed that increased throttling
doesn't dramatically impair noise characteristics like in prior art
solutions.
[0041] FIG. 3a-c shows the device 1 as described in FIG. 1a-c,
where the ring 11 is in a more throttled position than in FIG.
2a-c. It can still be seen that the inlet part 8 and the outlet
part 10 exhibits an asymmetrical cone shape and also that the
throttle part 9 mainly exhibits a form of a straight duct. Compared
to FIG. 2c, it also can be seen that the length of the throttle
part 9 is increasing the more the throttle device 7 is throttled,
which means that less turbulence is achieved in the throttle part 9
as the flow passage is getting longer, which is positive for noise
characteristics.
[0042] FIG. 4a-c shows the device 1 as described in FIG. 1a-c,
where the throttle device 7, i.e. the ring 11 is in a nearly closed
position. It is fully possible to close the airflow control device
1 totally.
[0043] FIG. 5a-c shows an alternative embodiment of the airflow
control device 1 with a similar design as described above with
reference to FIGS. 1-4. The difference is that the throttling
device 7 is a pivotable arc 12, instead of a ring. The arc 12 is
pivotable around the second pivot axis b in the same way as the
ring. The function and the possible variants of how to arrange the
pivotable arc 12 is applicable also with this variant in the same
way as it is at the ring-type (outside, inside, pocket etc.). In
the upright position, the airflow control device 1 is open for
airflow through the axial opening 4 in the inner tube 3.
[0044] FIG. 6a-c shows the device 1 as described in FIG. 5a-c,
where the throttle device 7, i.e. the arc 12 is in a slightly
throttled position. The arc-design gives another shape of the inner
tube 3 compared to the ring-design. While the ring-design gives a
similar but inverted inlet part 8 compared to outlet 10 part, with
an elongated throttle part 9 in between, the arc 12 gives an inlet
part 8 which differs from the outlet part 10, and the throttle part
9 is just the exact narrowest part, which is not elongated. The
arc-design of the throttling device 7 gives a possibility to choose
whether the pivoting motion of the arc 12 should be towards the air
flow direction or along the same, which may be of importance for
noise reduction. Still, the inlet part 8 as well as the outlet part
10 of the inner tube 3 exhibits an asymmetrical cone shape.
[0045] FIG. 7a-c shows the device 1 as described in FIG. 5a-c,
where the arc 12 is in a more throttled position than in FIG. 6a-c.
Compared to FIG. 6c it can be seen that the throttling part is
moved both in direction towards the airflow direction and also in a
radial direction, which means that the inlet part 8 is getting
shorter the more throttling of the airflow, while the outlet part
10 is getting longer.
[0046] FIG. 8a-c shows the device 1 as described in FIG. 5a-c,
where the throttle device 7, i.e. the arc 12 is in a nearly closed
position. It is fully possible to close the airflow control device
1 totally.
PARTS LIST
[0047] 1=airflow control device
[0048] 2=outer tube
[0049] 3=inner tube
[0050] 4=axial opening
[0051] 5=first end
[0052] 6=second end
[0053] 7=throttling device
[0054] 8=inlet part
[0055] 9=throttling part
[0056] 10=outlet part
[0057] 11=pivotable ring
[0058] 12=pivotable arc
[0059] 13=rotatable shaft
[0060] 14=actuator
* * * * *